// 封装倒计时逻辑函数

import dayjs from "dayjs";
import { computed, onUnmounted, ref } from "vue";

export const useCountDown = ()=> {
  // 1. 响应式数据
  let timer = null
  const time = ref(0)

  // 格式化时间为 xx分xx秒
  const formatTime = computed(()=>dayjs.unix(time.value).format('mm分ss秒'))

  // 2. 开启倒计时函数
  const start = (currentTime) => {
    // 开始倒计时的逻辑
    time.value = currentTime
    timer = setInterval(() => {
      time.value--
    },1000)
  }

  // 3. 组件销毁时清除定时器
  onUnmounted(()=>{
    timer && clearInterval(timer)//如果timer存在，则销毁
  })

  return {
    formatTime,
    start
  }
}